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left untouched until September 27th, 1914. By this date, i.e. more 
than twelve months afterwards, the lump of faeces was as hard as stone 
and had to be broken with a hammer; a small piece was chipped off 
and soaked in water in a watch-glass, as it softened it was broken up 
with a needle revealing numerous eggs containing shrivelled larvae. 
After about fifteen minutes the latter had appreciably swollen and soon 
regained their normal shape, they were moving actively within the egg¬ 
shells less than forty minutes after the commencement of the experiment. 
Another sample from the same dried mass was treated in a similar 
manner on April 30th, 1915, and yielded a number of live larvae which 
seemed none the worse for having been dried for twenty months. 
A number of experiments were also made to determine the effect 
of different temperatures on the ensheathed larvae, it was found that 
these, when perfectly dry, are able to withstand very high temperatures 
without losing their vitality. On one occasion seven dried larvae 
were kept for ten hours in an oven at a temperature of 60° C., when 
afterwards cooled and placed in water they all revived in less than 
half an hour and were still alive and active twenty-four hours after 
being remoistened. In the course of another experiment three dry 
larvae were subjected to a temperature of 70° C. for two hours, of these 
two revived and were swimming about actively twenty-five minutes 
after remoistening. 
Other experiments showed that this power of resisting high 
temperatures was confined to larvae in the dry condition, larvae in 
water are quickly killed if subjected to temperatures much over 50° C. 
The dried larvae of Nematodirus filicollis are equally resistant to 
cold, and several experiments showed that these could be left outdoors 
during sharp frosts in the winter without fatal consequences. 
The Completion of the Second Ecdysis. 
As already mentioned the ensheathed larvae of Nematodirus filicollis 
can live in w r ater for many months without undergoing any change, 
and in this medium at laboratory temperatures make no efforts to rid 
themselves of the closely-fitting sheaths formed during the second 
ecdysis within the egg-shell. This fact together with the similarity in 
structure and habits of these larvae with the ensheathed larvae of other 
better known worms of the same family (e.g. Haemonchus conlortus and 
Anchylostoma duodenale) leads to the conclusion that at this stage they 
have reached maturity and are ready to pass into the body of their 
definite host. 
